Devices and methods consistent with the present invention relate to switches and their manufacture and, more particularly, to a panel switch for use in electronic equipment, and methods of manufacturing the same.
Recently, a sheet-shaped panel switch has become widely used. For example, Japanese Patent Publication No. 2003-100165A describes a related art sheet-shaped panel switch.
FIG. 15 shows a perspective view of a related art panel switch and FIG. 16 shows an enlarged sectional view taken on line C-C in FIG. 15. The related art panel switch 51 includes a wiring board 52; a plurality of moving contacts 53 arranged on the wiring board 52; and a plurality of insulating film pieces 54a which are attached onto the wiring board 52 in such a manner that they cover the individual moving contacts 53.
As shown in FIG. 16, on the wiring board 52, a stationary contact 55 is provided for each of the plurality of moving contacts 53. The plurality of stationary contacts 55 are respectively provided by means of printing in a plurality of portions forming a switch portion on a surface of the sheet-shaped insulating film. Each stationary contact 55 includes an outside electrode 55a formed into a substantially annular shape and a central electrode 55b provided in a central portion surrounded by the outside electrode 55a. Although not shown in the drawings, the outside electrode 55a and the central electrode 55b are respectively connected to a connector terminal portion which is electrically connected to an external circuit.
Each moving contact 53 includes a lower side contact portion 53a which is formed as a circular-plate-shaped body formed out of an elastic metallic sheet, the shape of which is swelled into a dome-shape, so that it can be arranged on the outside electrode 55a of the wiring board 52; and an apex portion 53b arranged being opposed to the central electrode 55b. As noted above, the plurality of moving contacts 53 are arranged on the wiring board 52 corresponding to the plurality of stationary contacts 55.
Each insulating film piece 54a is formed by a flexible sheet-shaped insulating film that is divided into a plurality of sections which correspond to the plurality of moving contacts 53 by being cut into a predetermined size. On one side, i.e., an inside, of the insulating film piece 54a, an adhesive layer 56 (shown in FIG. 16) is provided. The insulating film piece 54a is attached onto the wiring board 52 by an adhesive force of the adhesive layer 56 which adheres the insulating film piece 54a to the moving contact 53.
Next, an operation of the related art panel switch 51 will be explained. If a pushing force is not given to the panel switch 51, the moving contact 53, being formed into a dome-shape, is swelled to the insulating film piece 54a side. Thus, the apex portion 53b of the moving contact 53 is separated from the central electrode 55b, and a state of switch-off is maintained. I.e., the switch is not conducting. FIG. 16 shows the related art panel switch 51 in the state of switch-off.
On the other hand, if the insulating film piece 54a is pushed onto the wiring board 52 side by a pushing force generally orthogonal to a plane of the wiring board 52, the insulating film piece 54a and the moving contact 53 are pressed downward along the dome-shape. Therefore, the apex portion 53b of the moving contact 53 comes into contact with the central electrode 55b and the switch is put into a state of switch-on. I.e., the switch conducts.
If the pushing force given to the insulating film piece 54a is released, the apex portion 53b of the moving contact 53 is returned to the initial position together with the insulating film piece 54 by an elastic returning force of the moving contact 53. Accordingly, the apex portion 53b is separated from the central electrode 55b again and the switch is put into a state of switch-off.
Next, referring to FIGS. 17 to 21E, a related art procedure for manufacturing the related art panel switch 51 will be explained. First, a sheet-shaped switch forming material M for forming the panel switch 51 is prepared. As shown in FIGS. 17 and 21A, the switch forming material M includes an insulating film 54, an adhesive layer 56, and a separator 52A. The adhesive layer 56 is provided on one side of the insulating film 54, and the separator 52A is provided on the other side of the adhesive layer 56. Thus, the adhesive layer 56 adheres the separator 52A to the insulating film 54. The insulating film 54 has a size capable of being divided into the plurality of insulating film pieces 54a. 
Next, as shown in FIG. 21B, the insulating film 54 and the adhesive layer 56 of the switch forming material M are cut into a predetermined size by using a metallic die (not shown). Thus, a plurality of divided insulating film pieces 54a are obtained. After that, as shown in FIG. 21C, the switch forming material M is inverted so that the separator 52A is located on the upper side and the insulating film pieces 54a are set at predetermined positions on a jig 57 in order.
Successively, the separator 52A is removed as shown in FIG. 18. Then, as shown in FIGS. 19 and 21D, the plurality of moving contacts 53, which are turned upside down, are arranged and made to adhere onto the insulating film pieces 54a so that the apex portion 53b of the dome-shaped moving contact 53 can be made to adhere onto the adhesive layer 56. An outside dimension of the moving contact 53 is set to be smaller than that of each insulating film piece 54a. Therefore, the moving contact 53 is covered with the corresponding insulating film piece 54a. 
After the plurality of moving contacts 53 have been made to adhere onto the adhesive layer 56, as shown in FIGS. 20 and 21E, the wiring board 52 is set on the plurality of moving contacts 53 and, the plurality of moving contacts 53 are adhered and fixed to the wiring board 52. It is also possible to use a separator 52B in place of the wiring board 52. In order to align the wiring board 52 with the sheet having plurality of moving contacts 53, two positioning pins 58 are arranged on the right and two positioning pins 58 are arranged on the left so as to be protruded from the jig 57. In other words, four positioning pins 58 in total are protruded from the jig 57. Accordingly, when the insulating film pieces 54a are put at predetermined positions on the jig 57, the positioning pins 58 provided on the jig 57 are inserted into positioning holes 59 provided on the wiring board 52, so that adhesion can be made under the condition that the insulating film pieces are properly positioned.
Next, an unnecessary portion of the wiring board 52 is removed by being cut off. For example, an unnecessary portion of the wiring board 52 corresponding to a portion between the moving contacts 53, which are adjacent to each other, is cut off. Finally, the insulating film pieces 54a are removed from the jig 57, and the related art manufacturing process of the related art panel switch 51 is completed.
However, the above-described related art panel switch and related art manufacturing process has a number of disadvantages. First, in the related art process of manufacturing the related art panel switch 51, it is necessary that a plurality of insulating film pieces 54a are punched from the insulating film 54 by using a metallic die and the thus insulating film pieces 54a are punched on the jig 56 in order. Accordingly, related art process requires many man-hours to produce the related art panel switch, thus increasing the manufacturing cost. Moreover, in the case where a profile of the insulating film piece 54a is changed, it is necessary to also change the metallic mold. Accordingly, this results in increased expenses and increased time for manufacturing. Lastly, the touch and feel of the related art panel switch is controlled by the dome-shaped moving contact, and accordingly, there is little variation possible in the touch and feel.